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T. B. ROBERTS.

ROTARY SHUTTLE FOR SEWING MACHINES. N0. 267;020. Patented NOV. 7, 1882.

WITNESSES: JNVENTOR A TTORNEYJZ N. Pzrzns, Phnla-hthognphar. Wnhilvglan, n, c 1

UNITED STATES PATENT OFFICE.

THOMAS E. ROBERTS, OF PITTSBURG, PA., ASSIGNOR OF TWO-THIRDS TO DAVID HUTOHISON AND JOSEPH M. MOFFAT, BOTH OF SAME PLACE.

ROTARY SHUTTLE FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 267,020, dated November 7, 1882. Application filed February 24, 1882. (No model] To all whatnot may concern Be it known that I, THOMAS B. ROBERTS, of Pittsburg, in the county ofAllegheny and State of Pennsylvania, have invented certain new and useful Improvements in Rotary Shuttles for Sewing-Machines; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same, reference being had to theaccompanying drawings, which form a part of this specification, in which- Figure 1 is an edge view of my shuttle. Figs. 2 and 3 are front and back views respectively. Fig. 4 shows in section the two parts separated with bobbin and tension in position. Fig. 6 shows the blank for tension and threadguide. Fig. 7 is a front view of same bent to shape. Fig. 8 is an edge view of same. Fig. 5 is an enlarged section of shuttle without bob- .bin or tension.

turbing its twist in either direction. Morev particularly my invention is as follows:

As before stated, this shuttle is in two parts or shells, A and B, both semi-spherical in shape and hollow, as shown. Shell A has the stern a, which is slitted at the'end and provided with projections 11, as shown in the enlarged view, Fig. 5, which forms a snapcatch to attach the shellA to shell B. The shell B has a hollow spindle, c, which fits over stem to of shell A, and has the recesses d to receive the projections or catches b of stem (1. By this construction the two shells are held together with sufficient force, but may be separated by simply giving them a smart pull apart. To efi'ect the revolution of both shells together, I provide the spindle c with one or more studs, 0, and at a corresponding point in the shell A, I

[locate one or more recesses, f, so that when the two shells are attached together the studs 6 and recesses f form a clutch or crab to insure simultaneous movement of the two shells. When thus locked together it will be observed that there is a slit between the rims of the two the shell B slightly larger than and overlapping shell A, for a purpose to be hereinafter explained. Shell B is provided with the loopcatcher or horn g, whose point is about on a line with the outer face of the shell, or slightly overhau gin g it, whence it retreats backwardl y, in a slanting direction, to the rim or lip of the shell, so that once the loop is caught the revo' lution of the shell forces the loop to follow along the inclined side of the horn g till the thread of the loop arrives at the rim of shell B, where it drops over the base of the horn, and which prevents it from slipping off the shuttle and dropping the stitch. After passing the horn the thread of the loop glides over the rim of shellB, and as it cannot return it is compelled to slide around the shell A, or, to speak more correctly, the effect is that the revolution of the horn 9 draws the loop in such manner as to envelop itself once every revolution. The overlapping of shell A by the rim of shell B renders this enforced path of the loop more certain, and renders it impossible for the loop-thread to drop into the space between the shells.

Before setting the shells A B together the bobbin 0 (having sufficient thread wound upon it) is slipped over the spindle c, and the end of the thread brought out through the circumferential slit between the shell-rims. Bobbin O is loose upon the spindle 0, so that while the spindle revolves as a part of shell B the bobbin may remain comparatively stationary, moving only enough to reel off its thread; but as a continued revolving of the spindle 0 would by friction soon impart a continuous movement to the bobbin, 1 insert a sort of brake or tension inside the shuttle. This tension conform shown at Fig. 6, which is bent up to form the two eyes i to ride upon the spindle c, and the end portions of the blank are brought toshells all the way aronnd;but I prefer to have sists preferably of apiece of sheet-steel of the gether and form the spring-lips k, which bridge the bobbin (J, as illustrated, the fork I being curved upwardly, as shown, under the lips k. The whole device z' k l, I call the tension and thread-guide. In inserting the bobbin 0 into the shells, the tension and thread-guide is set on the spindle. so as to straddle the bobbin. The thread of the bobbin is passed between the prongs of the guide-fork l, and then between the two spring-lips k, which press the thread between them with a light pressure. The two shells are snapped together after bringing the end of the thread outside. The shuttle-thread being brought up through the throat-plate, drawing it tight lifts the tension and guide It Z into a vertical position surmounting the bobbin G, and in about that position it remains while the shuttle revolves, delivering the thread as it is needed, allowing the bobbin to reel it off, but exercising a sufficient restraint upon the thread, and this without in any way twisting or untwisting the threada result of much importance and essential to the success of a rotaryshuttle.

The exterior of shell A may have the groove or furrow n, retreating spirally from a point under and slightly to the rear of the point where the inclined edge of the horn g terminates, so as to lead the loop properly.

The shuttle may be revolved by a crab 0r claw catching in depressions on the face of shell A, but allowing such play that the loop may pass between the claw ends and the shell without obstruction.

It will be seen that the tension or pressure on the thread varies itself automatically according to the thickness of the thread used. A thick thread passing through the lips will pull much harder than a fine thread, and this is as it should be in order to have a proper tension suited to the different sizes of thread. As no screws or other devices are used, but simply the natural spring of the lips, the tension is self-acting in the truest sense, and I therefore call it automatic. It is independent, for the reason that it is not permanently attached to the shuttle, but is simply contained therein, and moves at its own rate of speed independently of the revolution of the shuttle. While it is perhaps a part of the shuttle, and is necessary to it, yet it is dependent for action solely upon the thread paasing between its lips.

I claim as my invention 1. The rotary shuttle composed of the two hollow shells A B, having a thread-opening between them, anda bobbin-spindle, one of said shells having the projecting horn g, substantially as described.

2. In a rotary shuttle, the shell A, having spring-stem a, provided with catches b, in combination with shell B, having horn g, and hollow spindle 0, provided with recesses 01, substantially as described.

3. The rotary shuttle composed of the two hollow shells A B, having circumferential thread-opening between them, and a bobbinspindle, shell B, having horn g, and constructed with its rim overlapping that of shell A, substantially as described.

4. In a rotary shuttle carrying an inclosed bobbin, an automatic tension independent of the shuttle and inclosed therein, substantially as described.

5. In a rotary shuttle carrying an inclosed bobbin,an automatic tension and thread-guide independent of the shuttle and inclosed therein, substantially as described.

In testimony that I claim the foregoing as my own I have hereto affixed my signature in presence of two witnesses.

THOS. B. ROBERTS.

Witnesses:

T. J. MOTIGHE, THOMAS J. PATTERSON. 

